EVERETT — The big blue and white ship that’s been spotted off the Port of Everett has had some people asking: What is it and what’s it doing here?

Actually, the Aiviq (pronounced I-vic) has been docked off and on at the port’s Pier 3 for two and a half years, port spokeswoman Lisa Lefeber said.

Over the past few days, it has been doing anchor testing in a federal anchorage area, a type of parking lot for ships, outside Naval Station Everett, she said.

“There are U.S. Coast Guard-established parking lots for boats,” Lefeber said. “One is in Everett harbor.”

The Aiviq has been drawing attention in part because of its size — 360 feet in length and 80 feet wide.

Maxine Brink, who lives in Everett, said she’s seen the Aiviq “hovering in the bay.” For a while, it anchored in a spot across from Harborview Park, she said.

The ship generally is in Alaska from June through November or December and then returns to Everett over the winter, said Megan Baldino, a spokeswoman for Shell Oil Co.

During its stay in Everett, “it went out recently to test equipment,” she said. “As we get ready for 2015, it’s testing all its machinery,” and the crew is in training.

The ship received national attention for an incident in December 2012, when a mobile offshore drilling rig it was towing from Alaska to the Seattle area broke loose and ran aground in the Gulf of Alaska.

The U.S. Coast Guard investigated, a report last year noted that severe weather, the chosen route and reliance on one towing vessel were among factors that led to the grounding.

Pending successful permitting and the company’s determination that it can “explore safely and successfully,” the company plans on drilling in Alaska waters later this year, Baldino said.

The Aiviq is operating in the Everett area with a 22-member crew. It is conducting additional sea trials and will be underway periodically, Baldino said. It will be based out of the Port of Everett for the next couple of months.

The ship’s anchorage testing was scheduled to be completed by Wednesday, Lefeber said.

Sharon Salyer: 425-339-3486; salyer@heraldnet.com. The Associated Press contributed to this report.